RPG Defeat system and method

ABSTRACT

An RPG defeat system and method wherein a foam body is placed at a proximate a target. The foam body has a sufficiently low density to be pierceable by an RPG sensor without the RPG sensor being strained sufficiently to create a voltage. The foam body has a compressive strength sufficient to deform the RPG short circuiting a voltage pathway from the sensor to the RPG detonator. The foam body has a sufficient thickness and/or is spaced from the target to deform the RPG short circuiting the voltage pathway from the sensor to the RPG detonator before the sensor strikes the target and is strained creating a voltage.

RELATED APPLICATIONS

This application claims benefit of and priority to U.S. Provisional Application Ser. No. 62/256,896 filed Nov. 18, 2015 under 35 U.S.C. §§ 119, 120, 363, 365, and 37 C.F.R. § 1.55 and § 1.78 and which is incorporated herein by this reference.

GOVERNMENT RIGHTS

This invention was made with Government support from The U.S. Army Tank Automotive Research, Development And Engineering Center and CRADA #13-12. The Government of the United States has the right to practice or have practiced on behalf of the United States this subject invention throughout the world.

BACKGROUND OF THE INVENTION

RPG defeat mechanisms include slat armor, strangulation nets, and hard point nets. See, for example, German Patent DE 691,067, U.S. Pat. No. 1,385,897; WO2006/135432; WO2006/134407; and U.S. Pat. Nos. 8,443,708; 8,042,449; 8,857,309; 7,975,594; 8,011,285; 8,464,627; 8,893,606 and published U.S. Patent Application No. 2014/0041517 all incorporated herein by this reference. The main idea is to disable the RPG before it strikes its target by short circuiting the electrical connection between the RPG piezoelectric sensor and the detonator by deforming the RPG nose cone (ogive) or cover.

The best solutions minimize the chance that the RPG piezoelectric sensor will strike any portion of the defeat mechanism which would cause a detonation of the RPG while optimizing the likelihood that the defeat mechanism will disable the RPG before the RPG piezoelectric sensor strikes a target (e.g., a vehicle or structure) taking into account different RPG trajectories. Some prior solutions may not be optimized in this regard.

BRIEF SUMMARY OF THE INVENTION

Featured is an RPG defeat method comprising placing a foam body on or in proximity to a vehicle or structure. The method includes displacing a plug of the foam body allowing an RPG sensor to enter the foam body without the sensor signaling the RPG detonator. The foam body short circuits the electrical connection between the RPG sensor and detonator before the RPG sensor strikes the vehicle or structure.

Preferably, the foam body is chosen to have density sufficiently low to allow the RPG sensor to enter the foam body without the sensor signaling the RPG detonator. The foam body is chosen to have a density/strength sufficiently high for the foam body to short circuit the electrical connection between the RPG sensor and detonator before the RPG sensor strikes the vehicle or structure. If the foam body is on the vehicle or structure, the method may further include choosing a sufficiently thick foam body for the foam body to short circuit the electrical connection between the RPG sensor and detonator before the RPG sensor strikes the vehicle or structure. If the foam body is spaced from the vehicle or structure the method may further include choosing a sufficient spacing for short circuiting the electrical connection between the RPG sensor and detonator before the RPG sensor strikes the vehicle or structure.

The method may further include encapsulating the foam body. Also, the foam body is mounted in a framework secured to the vehicle or structure.

Also featured is an RPG defeat method comprising placing a foam body on or in proximity to a vehicle or structure. A plug of the foam body is displaced allowing an RPG sensor to enter a resulting channel in the foam body without the sensor signaling the RPG detonator. The foam body short circuits the electrical connection between the RPG sensor and detonator before the RPG sensor strikes the vehicle or structure by deforming the RPG nose cone as it enters the foam body.

Further featured is an RPG defeat system comprising a foam body on or in proximity to a vehicle or structure. The foam body is configured for displacement of a plug of the foam body allowing an RPG and sensor to enter the foam body without the sensor signaling the RPG detonator. The foam body is further configured to short circuit the electrical connection between the RPG sensor and detonator before the RPG sensor strikes the vehicle or structure.

The subject invention, however, in other embodiments, need not achieve all these objectives and the claims hereof should not be limited to structures or methods capable of achieving these objectives.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Other objects, features and advantages will occur to those skilled in the art from the following description of a preferred embodiment and the accompanying drawings, in which:

FIG. 1A is a schematic cross sectional side view showing an example of an RPG defeating panel in place on a vehicle or structure;

FIG. 1B is a schematic cross-sectional side view showing an example of an RPG defeating panel in a spaced relationship with respect to a vehicle or structure;

FIGS. 2A-2D are schematic cross-sectional side views showing an example of an RPG defeat method in accordance with an example of the invention;

FIG. 3 is a schematic three dimensional partially cut away view of an example of an RPG defeating encapsulated body for use in connection with a vehicle or structure;

FIG. 4 is a schematic three dimensional view of an example of an encapsulated RPG defeating body more particularly adapted to use in protecting structures;

FIG. 5 is a flow chart depicting the primary steps associated with an RPG defeat method in accordance with embodiments of the invention;

FIG. 6 is a schematic cross-sectional side view showing an example of an RPG defeating panel including subpanels or regions of different density;

FIG. 7 is a schematic view showing the RPG defeating panel of FIG. 6 with a plug readwardly displaced creating a channel for accepting the nose trigger of an RPG; and

FIG. 8 is a schematic view of an example of an RPG defeating panel including another kind of armor disposed between the target and the porous RPG defeating panel.

DETAILED DESCRIPTION OF THE INVENTION

Aside from the preferred embodiment or embodiments disclosed below, this invention is capable of other embodiments and of being practiced or being carried out in various ways. Thus, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. If only one embodiment is described herein, the claims hereof are not to be limited to that embodiment. Moreover, the claims hereof are not to be read restrictively unless there is clear and convincing evidence manifesting a certain exclusion, restriction, or disclaimer.

As shown in the example of FIG. 1A, porous (e.g., foam) body 10 may be secured on an external portion of a potential target such as vehicle or structure 12 (such as a vehicle door) or the foam body 10, FIG. 1B may be spaced from vehicle or structure 12 using, for example, a framework structure including fasteners 14 extending through foam body 10 and secured to vehicle or a structure 12.

Foam body 10, FIG. 2A is designed to allow RPG piezoelectric sensor fuse (trigger) 20 in or at the nose of the RPG to enter a channel 11 in the foam body 10 formed by displacing a plug 28, FIG. 2B of the foam body 10 material without the piezoelectric sensor 20 being strained and thus signaling the RPG detonator via a voltage. Thus, foam body 10 has a density sufficiently low such that the RPG piezoelectric sensor is not triggered as plug 28 is pushed out of foam body 10 and the nose of the RPG and the sensor enters channel 11, FIG. 2C. The shock wave 13 formed ahead of sensor 20 is believed to dislodge foam plug 28 and form channel 11 so RPG sensor 20 is not strained by any foam material as shown in FIG. 2C. The nose of the RPG may also dislodge foam plug 28.

Still, the foam body 10, FIG. 2D is designed to have a sufficient compressive strength to short circuit the electrical connection between the RPG sensor and detonator before the RPG sensor strikes the vehicle or structure the foam body is protecting. As shown in FIG. 2D, foam body 10 in the region around the channel 11 is sufficiently strong to deform one or more portions of nose cone 18 as shown at 30 a and 30 b as the nose cone enters the foam body via channel 11. The result is fuse disruption and defeating (duding) the RPG. When the RPG nose sensor now strikes the target (vehicle or structure) and generates a voltage, said voltage will not reach the detonator of the RPG because of the deformed ogive. Thus, the RPG shape charge will not detonate.

The foam body is also thick enough and/or spaced far enough away from the intended target so that the RPG fusing is disrupted before the RPG trigger strikes the target. If the foam body is located on the vehicle or structure it may need to be thicker (e.g., 5-6″ (127-152 mm) thick) than if the foam body is spaced from the vehicle or structure to allow for nose cone deformation and disabling of the RPG before the RPG piezoelectric sensor strikes the vehicle or structure. If, for example, the foam body is spaced from the vehicle or structure by 1-3″ (25-76 mm), the foam body may be 4″ thick. The thickness of the porous body may range from about 1″ thick to about 16″ (125 to 400 mm) thick.

In some examples, a foam body panel 10, FIG. 3 for use on a vehicle may include an environmental cover material such as encapsulant 40 for protection against the elements. One suitable encapsulant is a polymer or polyurea material typically used in the lining of pickup truck beds and industrial equipment. In FIG. 4, foam brick 10 for use in front of structures such as buildings also includes encapsulant 40.

One preferred foam body material is a styrene acrlonitrile (SAN) co-polymer foam. See U.S. Pat. No. 8,324,287 incorporated herein by this reference. A closed cell or open cell foam may be used. Other porous materials may be used (e.g., aluminum foams).

In testing, a SAN foam body 1-16 (25-400 mm) thick was spaced 0-6″ (0-152 mm) from a metal plate representing an RPG target. The foam body had a density range of 1 lbs/ft³ to 30 lbs/ft³, a compressive strength of 100-500 psi (0.7-3.4 Mpa), a compressive modulus (ASTM D1621-1973) of 10-25 ksi (69-172 Mpa), a shear strength of 150-250 psi (1.0-1.7 Mpa), a shear modulus of 4-9 ksi (27.8-62.1 Mpa), a tensile strength of 200-400 psi (1.4-2.8 Mpa), a tensile modulus of 12-29 ksi (82.7-200 Mpa) and a thermal conductivity of 0.01-0.1 W/mK and HDT of 85°−150° C.

RPG test shots were fired at the test structure and in each case the RPG was disabled by the foam body and did not detonate. The foam body caused fuse disruption and a defeat of each RPG.

Advantages over other RPG defeat mechanisms include the simplicity of the RPG defeating foam, its light weight, buoyancy, and ease of implementation. For example, the SAN foam disclosed above can be formed into different shapes.

Other porous bodies may also be used provided the armor does not cause the RPG piezoelectric sensor to trigger the RPG detonator and still the armor deforms the RPG nose cone sufficiently to short circuit the electrical connection between the RPG sensor and the detonator before the sensor strikes its intended target. Preferably, the foam material used has properties which allow the RPG to dislodge a plug of the foam material creating a channel just large enough in diameter for the RPG nose and sensor to enter. Preferably, in one example, the foam body alone defeats the RPG.

In one embodiment, after the RPG is fired at a target, step 50, FIG. 5, the RPG nose trigger enters a channel in the porous panel, step 52. The panel may be a foam block placed on or proximate the target. The channel in the panel is formed by a plug fully or partially displaced from the panel. Due to the characteristics of the panel, the nose trigger is not strained sufficiently to generate a voltage, step 54. The RPG continues to penetrate the panel, step 56 and due to the characteristics of the panel the RPG ogive is deformed by the material of the panel short circuiting the voltage pathway between the RPG nose trigger and the RPG detonator (typically located at the rear of the RPG), step 58. Eventually, the RPG nose trigger does strike the target, step 60 and is strained sufficiently to generate a voltage. But, since the RPG ogive is deformed, the voltage does not reach the RPG detonator and the RPG shape charge is not detonated.

Thus, the RPG defeating panel has a sufficiently low density to be pierceable by an RPG sensor without the RPG sensor being strained. Still, the foam body has a compressive strength sufficient to deform the RPG ogive short circuiting the voltage pathway from the sensor to the RPG detonator. Furthermore, the panel has a sufficient thickness and/or spacing from the target to deform the RPG short circuiting the voltage pathway from the sensor to the RPG detonator before the RPG sensor strikes the target and is strained creating a voltage.

In some examples, the porous body is uniform in structure. In FIG. 6, a porous RPG defeating shield 10′ includes subpanels or regions 70 a, 70 b of varying density. In one preferred example, subpanel or region 70 a is softer (e.g., a density less than 10 lbs/ft³ (160 Kg/m³)) and the subpanel or region 70 b is more rigid (e.g., a density greater than 20 lbs/ft³ (320 Kg/m³)).

The softer subpanel or region 70 a allows the RPG nose trigger to move a plug 28, FIG. 7 of the foam material rearward and allows the RPG trigger to enter the shield via the resulting channel 11 without straining the trigger. Softer subpanel or region 70 a also begins deforming the RPG ogive and subpanel or region 70 b then further deforms the RPG ogive short circuiting the voltage pathway from the RPG trigger to the RPG detonator. The rear region or subpanel 70 b, however, may have a lower density than the front region or subpanel.

In other embodiments, integrated rear armor 80, FIG. 8 may be used between the target 12 and the porous body 10″. Ceramic tiles, for example, may be used to protect against projectiles other than RPGs.

In still other examples, the target may be one or more panels of an amphibious vehicle. Here, the porous body provides buoyancy as well as protection against RPG threats (and, optionally, protection against other projectiles).

Although specific features of the invention are shown in some drawings and not in others, this is for convenience only as each feature may be combined with any or all of the other features in accordance with the invention. The words “including”, “comprising”, “having”, and “with” as used herein are to be interpreted broadly and comprehensively and are not limited to any physical interconnection. Moreover, any embodiments disclosed in the subject application are not to be taken as the only possible embodiments. Other embodiments will occur to those skilled in the art and are within the following claims.

In addition, any amendment presented during the prosecution of the patent application for this patent is not a disclaimer of any claim element presented in the application as filed: those skilled in the art cannot reasonably be expected to draft a claim that would literally encompass all possible equivalents, many equivalents will be unforeseeable at the time of the amendment and are beyond a fair interpretation of what is to be surrendered (if anything), the rationale underlying the amendment may bear no more than a tangential relation to many equivalents, and/or there are many other reasons the applicant can not be expected to describe certain insubstantial substitutes for any claim element amended. 

What is claimed is:
 1. An RPG defeat method comprising: placing a porous body on or in proximity to a vehicle or structure; displacing a plug of the porous body allowing an RPG sensor to enter a channel in the porous body without the RPG sensor signaling the RPG detonator; and the porous body short circuiting an electrical connection between the RPG sensor and detonator before the RPG sensor strikes the vehicle or structure.
 2. The method of claim 1 in which the porous body is made of foam.
 3. The method of claim 1 in which the porous body is chosen to have a density and strength sufficiently low to allow the RPG sensor to enter the porous body without the sensor signaling the RPG detonator.
 4. The method of claim 1 in which the porous body is chosen to have a density and strength range sufficient for the porous body to short circuit the electrical connection between the RPG sensor and detonator before the RPG sensor strikes the vehicle or structure.
 5. The method of claim 1 in which the porous body is on the vehicle or structure and the method further includes choosing a sufficiently thick body for the porous body to short circuit the electrical connection between the RPG sensor and detonator before the RPG sensor strikes the vehicle or structure.
 6. The method of claim 1 in which the porous body is spaced from the vehicle or structure and the method further includes choosing a sufficient spacing of the porous body for short circuiting the electrical connection between the RPG sensor and detonator before the RPG sensor strikes the vehicle or structure.
 7. The method of claim 1 further including encapsulating the porous body.
 8. The method of claim 1 in which the porous body is mounted in a framework secured to the vehicle or structure.
 9. The method of claim 1 in which the porous body is unitary in construction.
 10. The method of claim 1 in which the porous body has regions of different density.
 11. The method of claim 10 in which a forward region of the porous body has a lower density then a rearward region of the porous body.
 12. The method of claim 1 further including adding an armor layer between the porous body and the target.
 13. An RPG defeat method comprising: placing a porous body on or in proximity to a vehicle or structure; a plug of the porous body displaced forming a channel allowing an RPG sensor to enter the channel in the body without the sensor signaling the RPG detonator; and a porous body region proximate the channel deforming the RPG nose cone and short circuiting an electrical connection between the RPG sensor and detonator before the RPG sensor strikes the vehicle or structure.
 14. An RPG defeat system comprising: a porous body for placement on or in proximity to a vehicle or structure; the porous body configured for displacement of a plug of the porous body creating a channel in the porous body allowing an RPG sensor to enter the channel in the porous body without the sensor signaling the RPG detonator; and the porous body material proximate the channel configured to short circuit the electrical connection between the RPG sensor and detonator before the RPG sensor strikes the vehicle or structure.
 15. The system of claim 14 in which the porous body is made of foam.
 16. The system of claim 14 in which the porous body is chosen to have a density and strength sufficiently low to allow the RPG sensor to enter the porous body without the sensor signaling the RPG detonator.
 17. The system of claim 14 in which the porous body is chosen to have a density and strength range sufficient for the porous body to short circuit the electrical connection between the RPG sensor and detonator before the RPG sensor strikes the vehicle or structure.
 18. The system of claim 14 in which the porous body is for placement on the vehicle or structure and is sufficiently thick for the porous body to short circuit the electrical connection between the RPG sensor and detonator before the RPG sensor strikes the vehicle or structure.
 19. The system of claim 14 in which the porous body is to be spaced from the vehicle or structure and a sufficient spacing of the porous body short circuits the electrical connection between the RPG sensor and detonator before the RPG sensor strikes the vehicle or structure.
 20. The system of claim 14 further including a protective encapsulant about the porous body.
 21. The system of claim 14 further including a framework for the porous body secured to the vehicle or structure.
 22. The system of claim 14 in which the porous body is unitary in construction.
 23. The system of claim 14 in which the porous body has regions of different density.
 24. The system of claim 23 in which a forward region of the porous body has a lower density then a rearward region of the porous body.
 25. The system of claim 1 further including an armor layer between the porous body and the target.
 26. An RPG defeat system comprising: a foam body to be located at or proximate a target and having a sufficiently low density to be pierceable by an RPG sensor without the RPG sensor being strained sufficiently to create a voltage; the foam body having a compressive strength sufficient to deform the RPG short circuiting a voltage pathway from the sensor to the RPG detonator; and the foam body having a sufficient thickness and/or spacing from the target to deform the RPG short circuiting the voltage pathway from the sensor to the RPG detonator before the RPG sensor strikes the target and is strained creating a voltage.
 27. An RPG defeat method comprising: placing a foam body at a proximate a target, the foam body having a sufficiently low density to be pierceable by an RPG sensor without the RPG sensor being strained sufficiently to create a voltage; selecting the foam body to have a compressive strength sufficient to deform the RPG short circuiting a voltage pathway from the sensor to the RPG detonator; and selecting the foam body to have a sufficient thickness and/or spacing from the target to deform the RPG short circuiting the voltage pathway from the sensor to the RPG detonator before the sensor strikes the target and is strained creating a voltage.
 28. An RPG defeat system comprising: a panel to be located at or proximate a target and pierceable by an RPG sensor without the RPG sensor being strained sufficiently to create a voltage; the panel having a compressive strength sufficient to deform the RPG short circuiting a voltage pathway from the sensor to the RPG detonator; the panel having a sufficient thickness and/or spacing from the target to deform the RPG short circuiting the voltage pathway from the sensor to the RPG detonator before the sensor strikes the target and is strained creating a voltage; and the panel consisting essentially of foam.
 29. The system of claim 28 in which the panel further includes a protective liner.
 30. They system of claim 28 further including an armor layer between the panel and the target.
 31. The system of claim 28 in which the panel includes regions of different density. 